contrib/gcc-3.4/gcc/params.def

   1 /* params.def - Run-time parameters.
   2    Copyright (C) 2001, 2002 Free Software Foundation, Inc.
   3    Written by Mark Mitchell <mark@codesourcery.com>.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 2, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING.  If not, write to the Free
  19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  20 02111-1307, USA.
  21
  22 */
  23
  24 /* This file contains definitions for language-independent
  25    parameters.  The DEFPARAM macro takes 4 arguments:
  26
  27      - The enumeral corresponding to this parameter.
  28
  29      - The name that can be used to set this parameter using the
  30        command-line option `--param <name>=<value>'.
  31
  32      - A help string explaining how the parameter is used.
  33
  34      - A default value for the parameter.
  35
  36    Be sure to add an entry to invoke.texi summarizing the parameter.  */
  37
  38 /* The single function inlining limit. This is the maximum size
  39    of a function counted in internal gcc instructions (not in
  40    real machine instructions) that is eligible for inlining
  41    by the tree inliner.
  42    The default value is 500.
  43    Only functions marked inline (or methods defined in the class
  44    definition for C++) are affected by this, unless you set the
  45    -finline-functions (included in -O3) compiler option.
  46    There are more restrictions to inlining: If inlined functions
  47    call other functions, the already inlined instructions are
  48    counted and once the recursive inline limit (see
  49    "max-inline-insns" parameter) is exceeded, the acceptable size
  50    gets decreased.  */
  51 DEFPARAM (PARAM_MAX_INLINE_INSNS_SINGLE,
  52           "max-inline-insns-single",
  53           "The maximum number of instructions in a single function eligible for inlining",
  54           500)
  55
  56 /* The single function inlining limit for functions that are
  57    inlined by virtue of -finline-functions (-O3).
  58    This limit should be chosen to be below or equal to the limit
  59    that is applied to functions marked inlined (or defined in the
  60    class declaration in C++) given by the "max-inline-insns-single"
  61    parameter.
  62    The default value is 150.  */
  63 DEFPARAM (PARAM_MAX_INLINE_INSNS_AUTO,
  64           "max-inline-insns-auto",
  65           "The maximum number of instructions when automatically inlining",
  66           100)
  67
  68 /* For languages that (still) use the RTL inliner, we can specify
  69    limits for the RTL inliner separately.
  70    The parameter here defines the maximum number of RTL instructions
  71    a function may have to be eligible for inlining in the RTL inliner.
  72    The default value is 600.  */
  73 DEFPARAM (PARAM_MAX_INLINE_INSNS_RTL,
  74           "max-inline-insns-rtl",
  75           "The maximum number of instructions for the RTL inliner",
  76           600)
  77
  78 /* The maximum number of instructions to consider when looking for an
  79    instruction to fill a delay slot.  If more than this arbitrary
  80    number of instructions is searched, the time savings from filling
  81    the delay slot will be minimal so stop searching.  Increasing
  82    values mean more aggressive optimization, making the compile time
  83    increase with probably small improvement in executable run time.  */
  84 DEFPARAM (PARAM_MAX_DELAY_SLOT_INSN_SEARCH,
  85           "max-delay-slot-insn-search",
  86           "The maximum number of instructions to consider to fill a delay slot",
  87           100)
  88
  89 /* When trying to fill delay slots, the maximum number of instructions
  90    to consider when searching for a block with valid live register
  91    information.  Increasing this arbitrarily chosen value means more
  92    aggressive optimization, increasing the compile time.  This
  93    parameter should be removed when the delay slot code is rewritten
  94    to maintain the control-flow graph.  */
  95 DEFPARAM(PARAM_MAX_DELAY_SLOT_LIVE_SEARCH,
  96          "max-delay-slot-live-search",
  97          "The maximum number of instructions to consider to find accurate live register information",
  98          333)
  99
 100 /* This parameter limits the number of branch elements that the
 101    scheduler will track anti-dependencies through without resetting
 102    the tracking mechanism.  Large functions with few calls or barriers
 103    can generate lists containing many 1000's of dependencies.  Generally
 104    the compiler either uses all available memory, or runs for far too long.  */
 105 DEFPARAM(PARAM_MAX_PENDING_LIST_LENGTH,
 106          "max-pending-list-length",
 107          "The maximum length of scheduling's pending operations list",
 108          32)
 109
 110 DEFPARAM(PARAM_LARGE_FUNCTION_INSNS,
 111          "large-function-insns",
 112          "The size of function body to be considered large",
 113          3000)
 114 DEFPARAM(PARAM_LARGE_FUNCTION_GROWTH,
 115          "large-function-growth",
 116          "Maximal growth due to inlining of large function (in percent)",
 117          100)
 118 DEFPARAM(PARAM_INLINE_UNIT_GROWTH,
 119          "inline-unit-growth",
 120          "how much can given compilation unit grow because of the inlining (in percent)",
 121          50)
 122
 123 /* The GCSE optimization will be disabled if it would require
 124    significantly more memory than this value.  */
 125 DEFPARAM(PARAM_MAX_GCSE_MEMORY,
 126          "max-gcse-memory",
 127          "The maximum amount of memory to be allocated by GCSE",
 128          50 * 1024 * 1024)
 129 /* The number of repetitions of copy/const prop and PRE to run.  */
 130 DEFPARAM(PARAM_MAX_GCSE_PASSES,
 131         "max-gcse-passes",
 132         "The maximum number of passes to make when doing GCSE",
 133         1)
 134
 135 /* This parameter limits the number of insns in a loop that will be unrolled,
 136    and by how much the loop is unrolled.
 137
 138    This limit should be at most half of the peeling limits:  loop unroller
 139    decides to not unroll loops that iterate fewer than 2*number of allowed
 140    unrollings and thus we would have loops that are neither peeled or unrooled
 141    otherwise.  */
 142 DEFPARAM(PARAM_MAX_UNROLLED_INSNS,
 143          "max-unrolled-insns",
 144          "The maximum number of instructions to consider to unroll in a loop",
 145          200)
 146 /* This parameter limits how many times the loop is unrolled depending
 147    on number of insns really executed in each iteration.  */
 148 DEFPARAM(PARAM_MAX_AVERAGE_UNROLLED_INSNS,
 149          "max-average-unrolled-insns",
 150          "The maximum number of instructions to consider to unroll in a loop on average",
 151          80)
 152 /* The maximum number of unrollings of a single loop.  */
 153 DEFPARAM(PARAM_MAX_UNROLL_TIMES,
 154         "max-unroll-times",
 155         "The maximum number of unrollings of a single loop",
 156         8)
 157 /* The maximum number of insns of a peeled loop.  */
 158 DEFPARAM(PARAM_MAX_PEELED_INSNS,
 159         "max-peeled-insns",
 160         "The maximum number of insns of a peeled loop",
 161         400)
 162 /* The maximum number of peelings of a single loop.  */
 163 DEFPARAM(PARAM_MAX_PEEL_TIMES,
 164         "max-peel-times",
 165         "The maximum number of peelings of a single loop",
 166         16)
 167 /* The maximum number of insns of a peeled loop.  */
 168 DEFPARAM(PARAM_MAX_COMPLETELY_PEELED_INSNS,
 169         "max-completely-peeled-insns",
 170         "The maximum number of insns of a completely peeled loop",
 171         400)
 172 /* The maximum number of peelings of a single loop that is peeled completely.  */
 173 DEFPARAM(PARAM_MAX_COMPLETELY_PEEL_TIMES,
 174         "max-completely-peel-times",
 175         "The maximum number of peelings of a single loop that is peeled completely",
 176         16)
 177 /* The maximum number of insns of a peeled loop that rolls only once.  */
 178 DEFPARAM(PARAM_MAX_ONCE_PEELED_INSNS,
 179         "max-once-peeled-insns",
 180         "The maximum number of insns of a peeled loop that rolls only once",
 181         400)
 182
 183 /* The maximum number of insns of an unswitched loop.  */
 184 DEFPARAM(PARAM_MAX_UNSWITCH_INSNS,
 185         "max-unswitch-insns",
 186         "The maximum number of insns of an unswitched loop",
 187         50)
 188 /* The maximum level of recursion in unswitch_single_loop.  */
 189 DEFPARAM(PARAM_MAX_UNSWITCH_LEVEL,
 190         "max-unswitch-level",
 191         "The maximum number of unswitchings in a single loop",
 192         3)
 193
 194 DEFPARAM(HOT_BB_COUNT_FRACTION,
 195          "hot-bb-count-fraction",
 196          "Select fraction of the maximal count of repetitions of basic block in \
 197 program given basic block needs to have to be considered hot",
 198          10000)
 199 DEFPARAM(HOT_BB_FREQUENCY_FRACTION,
 200          "hot-bb-frequency-fraction",
 201          "Select fraction of the maximal frequency of executions of basic \
 202 block in function given basic block needs to have to be considered hot",
 203          1000)
 204 DEFPARAM(TRACER_DYNAMIC_COVERAGE_FEEDBACK,
 205          "tracer-dynamic-coverage-feedback",
 206          "The percentage of function, weighted by execution frequency, that \
 207 must be covered by trace formation. Used when profile feedback is available",
 208          95)
 209 DEFPARAM(TRACER_DYNAMIC_COVERAGE,
 210          "tracer-dynamic-coverage",
 211          "The percentage of function, weighted by execution frequency, that \
 212 must be covered by trace formation. Used when profile feedback is not available",
 213          75)
 214 DEFPARAM(TRACER_MAX_CODE_GROWTH,
 215          "tracer-max-code-growth",
 216          "Maximal code growth caused by tail duplication (in percent)",
 217          100)
 218 DEFPARAM(TRACER_MIN_BRANCH_RATIO,
 219          "tracer-min-branch-ratio",
 220          "Stop reverse growth if the reverse probability of best edge is less \
 221 than this threshold (in percent)",
 222          10)
 223 DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY_FEEDBACK,
 224          "tracer-min-branch-probability-feedback",
 225          "Stop forward growth if the probability of best edge is less than \
 226 this threshold (in percent). Used when profile feedback is available",
 227          80)
 228 DEFPARAM(TRACER_MIN_BRANCH_PROBABILITY,
 229          "tracer-min-branch-probability",
 230          "Stop forward growth if the probability of best edge is less than \
 231 this threshold (in percent). Used when profile feedback is not available",
 232          50)
 233
 234 /* The maximum number of incoming edges to consider for crossjumping.  */
 235 DEFPARAM(PARAM_MAX_CROSSJUMP_EDGES,
 236          "max-crossjump-edges",
 237          "The maximum number of incoming edges to consider for crossjumping",
 238          100)
 239
 240 /* The maximum length of path considered in cse.  */
 241 DEFPARAM(PARAM_MAX_CSE_PATH_LENGTH,
 242          "max-cse-path-length",
 243          "The maximum length of path considered in cse",
 244          10)
 245
 246 DEFPARAM(PARAM_MAX_CSELIB_MEMORY_LOCATIONS,
 247          "max-cselib-memory-locations",
 248          "The maximum memory locations recorded by cselib",
 249          500)
 250
 251 DEFPARAM(PARAM_MAX_LAST_VALUE_RTL,
 252          "max-last-value-rtl",
 253          "The maximum number of RTL nodes that can be recorded as \
 254 combiner's last value",
 255          10000)
 256
 257   /* INTEGER_CST nodes are shared for values [{-1,0} .. N) for
 258      {signed,unsigned} integral types.  This determines N.
 259      Experimentation shows 256 to be a good value.  */
 260 #ifdef ENABLE_GC_ALWAYS_COLLECT
 261 # define GGC_MIN_EXPAND_DEFAULT 0
 262 # define GGC_MIN_HEAPSIZE_DEFAULT 0
 263 #else
 264 # define GGC_MIN_EXPAND_DEFAULT 30
 265 # define GGC_MIN_HEAPSIZE_DEFAULT 4096
 266 #endif
 267
 268 DEFPARAM(GGC_MIN_EXPAND,
 269          "ggc-min-expand",
 270          "Minimum heap expansion to trigger garbage collection, as \
 271 a percentage of the total size of the heap",
 272          GGC_MIN_EXPAND_DEFAULT)
 273
 274 DEFPARAM(GGC_MIN_HEAPSIZE,
 275          "ggc-min-heapsize",
 276          "Minimum heap size before we start collecting garbage, in kilobytes",
 277          GGC_MIN_HEAPSIZE_DEFAULT)
 278
 279 #undef GGC_MIN_EXPAND_DEFAULT
 280 #undef GGC_MIN_HEAPSIZE_DEFAULT
 281
 282 DEFPARAM(PARAM_MAX_RELOAD_SEARCH_INSNS,
 283          "max-reload-search-insns",
 284          "The maximum number of instructions to search backward when looking for equivalent reload",
 285          100)
 286
 287 /*
 288 Local variables:
 289 mode:c
 290 End: */